1. Field of Invention
The invention relates to an apparatus for supporting a form member extending perpendicularly to the longitudinal axis of a form carrier. Such apparatus are generally called truss holders.
2. Description of Related Art
Such a truss holder is known, for example, from the preprint of the construction instructions "Truss form with wooden carriers (Unterzugschalung mit Holztragern)" (Status: March 1991) of the company Huennebeck-Roero GmbH. In this construction, the support member consists of a hollow profile with two blocks located thereon. The supporting frame is placed with these supporting blocks on the upper side of a profile transverse carrier of a truss form. A screw bolt is inserted through the hollow profile of the support member perpendicularly to the longitudinal axis of the profile transverse carrier, and a plate-shaped bracket is secured to the support member at its lower end. The bracket can be rotated between the hollow profile of the support member and the upper flange of the profile transverse carrier. Thus, by turning the bracket, its holding brackets can be engaged with the lower side of the upper flange of the profile transverse carrier. By tightening a wing-nut on the screw bolt, the truss holder can subsequently be tightened against the profile transverse carrier.
In tightening the truss holder against the profile transverse carrier, a clamping force is only applied in the direction parallel to the side face of the form skin. Consequently, there is no force component which can act directly against the concrete pressure on the side face. Therefore, it often arises that the side face of the form skin is pushed back a few millimeters in the direction of the profile transverse carrier when concreting the truss so that concrete escapes between the base plate and the form skin of the side face through the gap which has been created.
A truss holder is known from the Handbook 92 (Issue 1/92) of Peri GmbH by means of which clamping force components are applied in the direction parallel to as well as perpendicular to the side face of the form skin. On the supporting frame, a screw bolt is arranged in a direction inclined to the side face, a clamping hook being mounted to the lower end thereof. In this solution, two profile transverse carriers of the truss form are arranged in parallel directly adjacent one another and a perforated rail is inserted between both profile transverse carriers in the area beneath the base plate of the form skin. Respectively two truss holders arranged opposite one another on both side faces of the truss form are then braced by means of the clamping hooks hooked into the perforated rail.
In this construction, a further part in the form of the perforated rail is required in addition to the truss holder and a bracing of the truss holders can only ensue after both opposing truss holders as well as the perforated plate are mounted. Furthermore; respectively two profile transverse carriers must be arranged adjacent one another in order to be able to lay the truss holders and the perforated rail.